Which RVSM item is used to report altitude to air traffic control?

Which RVSM item is used to report altitude to air traffic control?

• A. Altitude Alerter
• B. Autopilot
• C. Pitot Heaters
• D. Altitude Transponder

Answer: (D)

Altitude data reported to air traffic control in RVSM airspace comes from the altitude transponder. This device replies to radar interrogations with the aircraft’s encoded altitude (Mode C, and Mode S if equipped), giving ATC a precise vertical position to maintain the required separation between flight levels. The other items don’t provide that data to ATC: an altitude alerter is a cockpit warning tool for altitude constraints, not a transmitter to ATC; the autopilot handles flight path and altitude control but doesn’t report altitude to ATC; pitot heaters prevent pitot tube icing to ensure accurate airspeed readings, not altitude reporting.

Altitude data reported to air traffic control in RVSM airspace comes from the altitude transponder. This device replies to radar interrogations with the aircraft’s encoded altitude (Mode C, and Mode S if equipped), giving ATC a precise vertical position to maintain the required separation between flight levels. The other items don’t provide that data to ATC: an altitude alerter is a cockpit warning tool for altitude constraints, not a transmitter to ATC; the autopilot handles flight path and altitude control but doesn’t report altitude to ATC; pitot heaters prevent pitot tube icing to ensure accurate airspeed readings, not altitude reporting.